The present invention relates to a high pressure coupling apparatus and particularly to a releasable coupling of a pair of pipe sections located in axially end-to-end relationship.
High pressure flow systems may employ suitable conduits which are releasably interconnected for relatively short periods of time. A particular example which has recently been developed is in pumping of concrete on site. In such systems, the concrete may be trucked or otherwise delivered to the installation site and then transferred to the actual drop location through a pressurized pumping system. Each installation is generally unique to the particular installation. In practice, the required system is made from a plurality of standardized pipe sections which are releasably interconnected through a quick coupler for subsequent assembly. For example, U.S. Pat. No. 3,705,737, which issued Dec. 12, 1972 to Robert E. Westerlund et al., discloses a releasable hinged coupler for interconnecting of the adjacent end of a concrete pumping conduit and the like. In accordance with more or less conventional practice, the encircling coupler halves or sections are formed with a generally U-shaped cross-section defining outer depending leg portions which project into corresponding annular grooves formed in the adjacent pipe ends. A sealing gasket is located within the U-shaped sections banding the joint between the pipe sections to further seal the joint. The gasket is employed to create a minimum gap or volume while maintaining an essentially complete fluid type enclosure. This is significant to minimize possible material loss and long life in the connection. The coupler employs an over-center toggle latch to permit tight closure of the coupler onto the pipe ends. Although such couplers have found wide acceptance in the industry, a continuing problem exists in the field with respect to the life of the structures. Thus the continued reuse with the assembly and disassembly of the pipe section tends to result in a disruption of the sealing surfaces such as a rolling of the adjacent edges. This may result in a slight offset of the coupling with a weakened juncture. Under high pressure pumping, particularly with very long lines where high pressure surges are encountered, disruption of the joint may actually occur with a consequent resulting loss of material and, more important, significant down time of the total system while the joint is repaired. Thus, very special care is normally taken in checking the coupler and pipe ends to maintain reliable pumping continued operation. However, such systems are inherently dependent upon the reliability and skill of the workmen.